Conveyor In, Conveyor Out and Buffer all run continuously. Sachets flow one-by-one, staggered across MC1–MC10. The Case Packer conveyor is the exception — it indexes intermittently, stepping forward only once its current pocket is filled. Watch for sachets bunching up (at risk) vs. flowing smoothly.
Conveyor In, Conveyor Out and Buffer are plain constant-speed belts — the same sizing logic as before applies to them. The Case Packer is different: it holds fixed pockets that must be presented stationary to be loaded, so it physically has to stop-index-stop rather than run continuously.
Same derivation as before: Conveyor In supplies every pusher's combined demand, Conveyor Out carries the full merged output after MC-N, and the Buffer runs at the same speed to hand off smoothly in normal operation.
Each time a sachet reaches the front pocket, the case packer loads it, then indexes forward by one pocket
pitch before it can accept the next one. If the "index time / pocket" you set is slower than
60 / Q_total seconds, the case packer can't keep pace with what's arriving — sachets queue up at its
entrance, and if the buffer isn't long enough to absorb that queue, it backs up into Conveyor Out. Try dragging
the index-time slider up in the simulation and watch this happen.
This sizes the buffer to absorb a genuine case-packer stoppage (jam, case change) for the target hold-up time without backing sachets into Conveyor Out. It's worth noting this formula only depends on total throughput and pack pitch — not on how sachets are fed into the machines — so Option 2 (synchronized batch feed) needs the same buffer length for the same hold-up target, even though its Conveyor In/Out run much slower. What differs between the two options is upstream conveyor speed, not buffer capacity.
| Quantity | Value |
|---|---|
| Combined throughput | |
| Pack pitch | |
| Conveyor In/Out/Buffer speed | |
| Max case-packer index time to keep up | |
| Recommended buffer length (15 s) |